This relates generally to imaging systems and, more particularly, to imaging systems that have symmetrical pixels.
Modern electronic devices such as cellular telephones, cameras, and computers often use digital image sensors. Image sensors (sometimes referred to as imagers) may be formed from a two-dimensional array of image sensing pixels. Each pixel includes a photosensitive layer that receives incident photons (light) and converts the photons into electrical charge. Image sensors are sometimes designed to provide images to electronic devices using a Joint Photographic Experts Group (JPEG) format.
Conventional image sensors may include imaging pixels with floating diffusion regions. Charge generated in the photosensitive layers may be transferred to the floating diffusion regions for subsequent readout. In conventional imaging pixels, floating diffusion regions are typically formed in the corner of imaging pixels. However, this leads to asymmetries in the pixel, which can cause image artifacts and reduced versatility of the pixels. Additionally, in conventional image sensors it can be difficult to enclose photodiodes with deep trench isolation (DTI).
It would therefore be desirable to provide improved imaging pixels for image sensors.